Power in the Golf Swing....

[titleist981]

I'm missing something here... does power in the golf swing come from turning the hips out of the way and throwing the body and hands at the ball towards the target (per Rory McIlroy). what are other recipes for power and consistency? I seem to be lacking in both,...

 

[WILDTHING]

This might help explain how Jon Rahm and possibly other PGA tour players create clubhead speed. It might also explain why LPGA women (who have faster pelvic rotation and slightly inferior ribcage rotation ) cannot drive the ball as far as PGA men (ie. 'stretch shorten cycle' loading in the wrists). LPGA women have far inferior wrist uncocking speed in the downswing than PGA men and also have 50% greater injuries to their wrists.





Below is an explanation from a poster on another forum which I think is a fantastic summary of the video:

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In this video (at 2:57) from TPI, Greg Rose says that muscles are like rubber bands. He, of course, knows this is not exactly true, it is just an easy-to-visualize analogy. In reality, muscles create an elastic band like effect via muscle activation and generating force. Muscles don't stretch and snap back, like a simple rubber band. For example, when jumping, the gluteus maximus and rectus femoris generate force eccentrically to control increased hip and knee flexion to squat down slightly, often called the "stretch phase". Immediately following this lowering or stretching phase, these same muscles activate and shorten concentrically and generate explosive force to jump upward. This dynamic process is often called the "stretch-shorten cycle", or the "load and explode cycle", or the "eccentric-concentric cycle".

This is valuable because a dynamically activated muscle in a stretched position can generate a greater shortening force and movement acceleration than can a non-stretched muscle, all else being equal. So, in terms of human performance, the stretch-shorten cycle is often beneficial, since faster, stronger, more powerful motion usually leads to better results.

In the golf swing, these stretch-shorten cycles are also based on muscle activation, but here, the term "separation" is also used. Again, muscles are not elastic bands, they can only generate force and movement to bring about an elastic band like effect.

Greg Rose discusses a common example of separation that occurs during the backswing and downswing, as illustrated in Jon Rahm's swing. From p1 to p4, muscle activation causes the upper torso to rotate about 90 degrees and the pelvis/hips to rotate about 45 degrees. This 45 degree difference or separation creates a stretching of the oblique abdominal muscles, preparing them to shorten quickly during the downswing. However, more torso-pelvic separation can occur between p4 and p4.5, which may create an even more effective contraction of the obliques muscles during the initial downswing. The stretched-shortening oblique muscles can then quickly rotate the rib cage CCW, which can quickly move the left arm (connected to the left rib cage via the left scapula), which can quickly move the left hand (connected to the left arm and forearm) during the early downswing. Of course, this is assuming proper muscle tension exists across each applicable joint to efficiently transfer motion along this kinetic chain.

Greg Rose also provides a second and third "separation" example is this video. The second example is increased left arm adduction during the transition as the upper torso is rotating CCW, in the opposite direction. During this time, in some players like Jon Rahm, the upper torso moves slightly faster than the left arm, creating the increased separation. This slightly stretches specific muscles (left latissimus dorsi, teres major, etc.) crossing the left shoulder joint, priming them to activate and generate a heightened concentric muscle contraction, to potentially augment left arm abduction speed during the early downswing.

The third, and final example, is increased separation (lag) between the left wrist and club shaft. Here, illustrated in Jon Rahm's swing, the left forearm/hand is moving slightly faster than the club shaft, which in those with optimal wrist range of motion, can increase left wrist radial deviation, and lead to greater separation between the left forearm/hand and club shaft. This stretches the muscles that cause ulnar deviation, that can then contract concentrically during the downswing to possibly assist in a more efficient release of PA#2 after p5.5 (although we know that the release of PA#2 can occur passively, with no needed muscular input). Most certainly the main advantage of this left hand and club shaft separation is the increased lag angle generated during the transition and early downswing, since a significantly greater range of motion release of the left wrist via ulnar deviation leads to a significantly greater increase in club head speed from p5.5 to p7.

A stretch-shorten cycle, Greg Rose doesn't mention, is the squat move. As discussed above, some players will flex at the hip joint during the transition via eccentric muscle activation. This will lower the body a few inches closer to the ground from p4 to p5.5. After p5.5, the left hip can begin to straighten or extend as the left hip rotates CCW. Based on the stretch-shorten cycle, a stretched left gluteus maximus could be primed to contract concentrically more effectively at p5.5, possibly increasing the efficiency of this hip extension motion. However, it is difficult to conceive how this could increase club head speed since hip extension should always occur relatively late in the downswing, well past its window of opportunity to significantly increase swing speed.

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I was able to try and explain how left hip and leg extension in the later downswing might increase clubhead speed (note I made an error in my wording about the red arrow being the tension in the club).

Note : I made a mistake with that red arrow . That is not the tension force in the shaft (which is normally in the direction of centripetal pull) . That red force is the equal and opposite force that is applied to the hands by the club. The hands pull on the club , but the club also pulls on the hands according to Newton's 3rd Law

Addendum: I think my image above might not actually increase speed by very much in the late downswing because the club is already moving so fast that there may not be enough time to angularly accelerate the club by any significant amount before impact. The actual major 'up force' across the grip happens before the golfer reaches the position on the far left image.

 

[blugold]

The biggest factor of power in the golf swing, any athletic endeavor really, is the one nobody wants to talk about.

Genetically assigned neuromuscular efficiency, your mom and dad, are the biggest factors for power. Type IIx muscle fibers determine power more than any other factor.

 

[TxAggie2018]

The biggest factor of power in the golf swing, any athletic endeavor really, is the one nobody wants to talk about.

Genetically assigned neuromuscular efficiency, your mom and dad, are the biggest factors for power. Type IIx muscle fibers determine power more than any other factor.

^^^

That's why the NFL loves scouting college players on their broad jumps and vertical jumps. Fast-twitch explosive power is effectively untrainable.

 

[blugold]

^^^

That's why the NFL loves scouting college players on their broad jumps and vertical jumps. Fast-twitch explosive power is effectively untrainable.